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Following from the previous two questions about Anabaena, would you find mRNA that is different between these two cell types, photosynthetic and nitrogen fixing heterocyst? If so, what would it represent?

In bacteria, DNA binding proteins and alternative sigma factors play an important role in ______.

You conduct an Ames test on a chemical you suspect might be a carcinogen. Following incubation, you find some colonies on your control plate. Why do you see some colonies on your control plate?

Consider the cyanobacteria Anabaena. Individual cells grow attached to each other in long chains produced from binary fission with cells remaining attached (e.g., streptococcus). Most perform photosynthesis, using photosystems I and II to generate ATP and NADPH that they use to power the fixation of carbon dioxide via the Calvin cycle. However, a small number form heterocysts, cells that instead of performing photosynthesis, fix nitrogen into ammonium. Heterocysts share their nitrogen compounds with their photosynthetic neighbors, who in turn share sugars with the heterocysts. If you extracted all the mRNA from a single heterocyst, and all the mRNA from a single photosynthetic cell, what information would this give you, i.e., what would this tell you about them?

Consider the following phenotypic identification examples and types. Match each example with the type of approach it represents.

The World Health Organization declared smallpox eradicated in 1980. This represented a major victory in global health and accomplished a substantial reduction in human misery and suffering, becoming the first and so far only infectious human disease to be completed ended. Imagine you join a team tasked with eradicating the next human disease! Briefly consider each of the following diseases and how you might completely end them so they would never infect another human. Pick only one of these diseases and answer the questions below. A) Malaria, caused by species of Plasmodium, a protist transmitted by mosquito vectors in the genus Anopheles. B) Chagas disease, caused by the protozoan Trypanosoma cruzi and transmitted by the triatomine bug,  C) Dracunculiasis (Guinea-worm disease), caused by Dracunculus medinensis, a nematode (worm) that spends part of its life cycle in copepods (small curstaceans) and infects humans when they drink water containing the copepods.  D) Anthrax, caused by Bacillus anthracis, an endospore-forming Gram positive rod-shaped bacteria found globally in soils. E) Rabies, caused by Rabies lyssavirus, an enveloped single-stranded negative-sense RNA virus found in wild and domesticated animals (e.g., bats, raccoons, skunks, foxes, dogs, and many more).   Please answer the following FOUR questions. Number your answers 1 through 4. 1. Pick a single disease from the above list and describe approaches you might use to eradicate it. 2. For that same disease you chose in the previous question, what aspects of the pathogen or its life cycle might make its eradication especially difficult? 3. Of the five diseases listed, which do you think would be the easiest to eradicate, and why? 4. Of the five diseases listed, which do you think would be the most difficult to eradicate, and why? Note there is not a single correct answer, but you should explain and defend your reasoning. Please be sure to number your answers 1 through 4, and answer all four parts of this clearly, in full complete sentences, in full complete paragraphs, one paragraph per question.

Janthinobacterium lividum is a Gram negative bacterium that produces a dark violet compound called violacein that possess antiviral, antibacterial, and antifungal properties. You are interested in finding gene(s) responsible for the production of violacein. You transform a culture with a plasmid containing a transposon and an ampicillin resistance gene (bla). Realizing your transformation efficiency will be low, how might you identify bacteria that have been successfully transformed?

Consider a population of E. coli mutants that have a defect in their lacI gene, resulting in the production of a repressor protein that binds to the operator of the lac operon, but does not bind to lactose itself. If you placed these cells in a growth media containing lactose, what would happen?

Which of the following contributes to healthcare-associated infections?

Optional 2 points of extra credit: Write your own short answer or essay question, and then answer it! Relax; this is meant to be a “choose your own topic” like on the last exam, but worded slightly differently for hopefully better success on my part. Alternately, pick any one topic you studied for this exam but I didn’t ask, and explain that topic to demonstrate your knowledge of it. Please write a complete answer that is a full paragraph with a minimum of 4-5 sentences; do not use bullet points! Note the question is set to 0 points so that it will count as actual extra credit (numerator only, not denominator) when I grade these.